Which of the following is a correct statement about spray gun classifications?

• A. There are two main classes: suction feed and pressure-feed spray guns
• B. There are three main classes: gravity feed, siphon feed, and HVLP
• C. Spray guns are never used for exterior coatings
• D. All spray guns are identical in operation

Answer: (A)

Spray gun classifications focus on how the coating is fed into the nozzle. The practical split is into suction feed (often called siphon feed) and pressure-feed. In suction feed, the cup is below or on the gun and the airstream creates suction that pulls the coating up into the nozzle, with gravity assisting the flow. In pressure-feed, the cup is pressurized so the coating is forced into the nozzle by air pressure, which is useful for thicker materials and larger jobs.

This is why the statement about two main classes is the best fit: it reflects the fundamental difference in how material reaches the atomizing area, which drives performance and application.

The idea of three main classes mixing gravity feed, siphon feed, and HVLP isn’t accurate because gravity feed and siphon feed describe the same suction mechanism, and HVLP is a performance/pressure characteristic rather than a separate primary feed category. Exterior coatings are routinely applied with spray guns, and spray guns are not identical in how they operate, since they differ in feed method, nozzle size, and operating pressure.